The present invention concerns a valve enabling the passing of a fluid in a determined direction as a function of an over-pressure. An application may be found for such a valve in electrochemical storage batteries for removing the gases which could be accumulated in cells thereof, at the end of the charge, during the over-charge and in the case of inversion.
Objects and features of the present invention are to provide a common exhaust valve for several cells of a same battery which will permit venting of gas independently from each cell irrespective of gas conditions in other cells of the battery.
One form of valve comprises a chamber communicating freely with a first space and communicating, moreover, with a second space. The chamber contains an elastically deformable part. This part is capable of stopping up the passage between the chamber and the second space, e.g. in a cell, when the excess of pressure prevailing, e.g., in the second space in relation to the pressure prevailing in the chamber is lower than a first predetermined value; it frees the passage by elastic deformation when the excess of pressure in the second space is higher than a second determined value, thus enabling the escaping of a fluid from the second space towards the first space. The said second value in that at which the valve opens, when the pressure in said second space increases. The first value is that at which the valve closes, when the said pressure again decreases. These two values may be identical or different. In the latter case, when the pressure is comprised between them, the valve may be open or closed according to the previous variation in the pressure. A valve according to the invention is characterized more particularly in that the chamber communicates with at least a third space, e.g. a second cell, the corresponding passage therefrom to said chamber being either stopped up or freed by the same elastically deformable part under like pressure value conditions as is the passage between the chamber and the first named second space. Thus, the single part in said second chamber is responsive to pressure differentials between the said chamber and those in the second and third spaces independently.
Another object and feature of the invention is also the provision of such a valve in a one-piece battery comprising at least two storage cells and whose case has two compartments respectively containing the two storage cells and constituting the second and third spaces previously defined. In that case, the valve chamber communicates on the one hand with the two compartments and on the other hand with the first space which may be the atmosphere. The communication with the atmosphere may be effected either by an opening formed in the lid or in the bottom of the casing.
In relation to conventional constructions having a valve for each storage cell, the present invention enables a reduction of costs, since only one single deformable part is required with a consequent saving of space which is all the more appreciable as the dimensions of the storage cells are smaller.
A valve according to the invention may be applied to a one-piece battery comprising any number of compartments provided respectively with means for leading the gases up to the chamber of the valve which is common to all the cells. It may be used, to great advantage, for four storage cells having a parallelepipedical shape with a common ridge. It is then placed at one of the ends of that ridge and the leading means are constituted simply by orifices made through the walls. In a battery having more than four storage cells, as many valves as there are sets of four storage cells may be provided.